Geotechnical data compilation for evaporitic rocks in Abu Dhabi, UAE: A resource for engineers

The durability and degradability of evaporitic rocks are always a critical concern in geological, civil, and geotechnical engineering applications, necessitating careful consideration for reliable, secure, and sustainable construction. This dataset is based on a comprehensive collection of geotechnical data involving both mechanical and physical properties as well as geochemical analyses for the evaporitic rocks in Abu Dhabi and its vicinity. The purpose of this dataset is to be an important source for construction professionals, engineers, and decision-makers in the region by providing basic insights into the challenges associated with building projects on and in evaporitic rocks. This data is obtained from extensive field investigations and laboratory analyses and will help to ensure that construction activities are carried out safely and efficiently when dealing with evaporitic rock formations. The prevalence of evaporitic rocks in Abu Dhabi highlights the importance of this geotechnical data compilation in facilitating informed decision-making and supporting safe construction.


a b s t r a c t
The durability and degradability of evaporitic rocks are always a critical concern in geological, civil, and geotechnical engineering applications, necessitating careful consideration for reliable, secure, and sustainable construction.This dataset is based on a comprehensive collection of geotechnical data involving both mechanical and physical properties as well as geochemical analyses for the evaporitic rocks in Abu Dhabi and its vicinity.The purpose of this dataset is to be an important source for construction professionals, engineers, and decision-makers in the region by providing basic insights into the challenges associated with building projects on and in evaporitic rocks.This data is obtained from extensive field investigations and laboratory analyses and will help to ensure that construction activities are carried out safely and efficiently when dealing with evaporitic rock formations.The prevalence of evaporitic rocks in Abu Dhabi highlights the importance of this geotechnical data compilation in facilitating informed decision-making and supporting safe construction.
© 2024 The Author(s).Published by Elsevier Inc.This is an open access article under the CC BY license ( http://creativecommons.org/licenses/by/4.0/ ) Specifications

Value of the Data
• In Abu Dhabi, a rapidly developing region with extensive infrastructure projects where evaporitic rocks are prevalent, their study provides a significant contribution to the region.The unique challenges posed by evaporitic rocks in Abu Dhabi, such as their easily degradable nature leading to surface subsidence, sinkhole formation, and landslides.Construction businesses, engineers, and decision-makers can benefit greatly from the insights gained, particularly in addressing foundation issues at construction sites.• Raw datasets obtained from extensive field investigations and laboratory analyses are presented on geotechnical (mechanical and physical) properties and geochemical composition measured in evaporitic rocks from Abu Dhabi and its vicinity, UAE.This data will help to ensure that construction activities are carried out safely and efficiently when dealing with evaporitic rock formations.• The geotechnical data presented in this dataset will be essential tools for navigating the difficulties of construction in Abu Dhabi and its vicinity.• This geotechnical data compilation for evaporitic rocks emerges not only as a scholarly endeavor but as a feasible resource for informed decision-making in the engineering and construction sectors in this region.• As urban areas expand, this compilation is a valuable resource for construction businesses, engineers, and decision-makers in Abu Dhabi, providing essential information for safe and effective construction practices in the presence of evaporitic rocks.• The presented dataset can be freely and easily used by interested readers.The geochemical data can potentially be correlated with geotechnical parameters.This correlation can be utilized to predict certain geotechnical properties of evaporitic rocks, such as strength, durability, and rock-water interaction, which are crucial for engineering design.

Background
In arid regions, the investigation of evaporitic rocks provides useful information due to their complexity and diverse geological, environmental, and geotechnical contributions [2][3][4][5][6] .This distinction points out the need for a comprehensive study that not only addresses origin and paleoenvironmental conditions but also addresses engineering issues, particularly in construction [6][7][8] .
The importance of understanding the mechanical and physical properties of evaporitic rocks is important for engineers and construction professionals [ 9 , 10 ].Geotechnical data facilitates quantitative analysis, providing insights into long-term behavior, stability, and resource management [ 11 , 12 ].These implications extend beyond the immediate regions, resulting in a better understanding of evaporite sequences worldwide [13] .The examination of geotechnical data is a key factor in determining the durability of subsurface evaporitic rocks and underground structures.This knowledge provides the basis for comprehensive risk assessment and early risk mitigation [ 2 , 14-16 ].Furthermore, examining the geotechnical aspects of evaporitic rocks sheds light on their stability over geological time, aqueous geochemistry, water-rock interactions, and stress redistribution during excavation [17][18][19] .These aspects are important to understand the geotechnical properties of the surrounding rocks, thus influencing construction practices.

Data Description
The dataset [1] encompasses a wide array of mechanical properties, including Uniaxial Compressive Strength (UCS), Point Load Index (PLI), Indirect Tensile Strength (ITS), Schmidt Hardness Value (SHV), Sonic Wave Velocity (SWV), and Slake Durability Index (SDI).These properties provide essential insights into the strength, durability, and deformation characteristics of the evaporitic rocks, forming the basis for engineering design and risk assessment.In addition to the mechanical properties, the dataset examines key physical attributes, such as Density ( ρ), Unit Weight ( γ ), Specific Gravity (G s ), Water Content (W c ), Porosity (n), and Void Ratio (e).These parameters offer a comprehensive understanding of the rock's mass, volume, and water-related characteristics, contributing to the assessment of resistance, permeability, and overall geological stability.These data were modeled and validated using HYFIS vs FMR, LWR, and Least squares regression methods [20] .Furthermore, the geochemical composition (major elements) of the investigated evaporitic rocks is presented.The geochemical composition of these rocks provides important information about their chemical characteristics, which is required to assess their suitability for various geotechnical applications by predicting any potential reactions or alterations to determine their environmental stability under specific conditions.
The data obtained from each analysis are presented and described in dataset Tables 1-3 [1] .The dataset directory structure is as follows: -Table 1.xlsx:A file representing the mechanical parameters test results of evaporitic rocks, Abu Dhabi.-Table 2. xlsx: A file representing the physical parameters test results of evaporitic rocks, Abu Dhabi.-Table 3. xlsx: A file representing the concentration of major elements (oxides%) of evaporitic rocks, Abu Dhabi.

The study area and field sampling
The land surface of Abu Dhabi and its vicinity is predominantly composed of a 1-2 m thick gypcrete soil derived from recent eolian.The soil is covered by approximately 2 m of dune sand.The gypcrete soils are underlined by a sequence of Lower Miocene evaporitic rocks (18-20 m thick) [ 6 , 8 ].
Detailed field investigations of evaporite rocks were conducted at twenty-seven different locations in Abu Dhabi (L1-L27) ( Fig. 1a and Table 1 ).149 representative evaporitic rock blocks were collected from temporary excavations and boreholes that reached depths of up to 20 m ( Fig. 1b , c ). Evaporitic rock blocks were carefully inspected and those without visible defects such as cracks, fractures or alteration zones were transported to a laboratory and stored under laboratory conditions ( Fig. 1d -f ).

Experiments
Evaporite rock blocks without major macroflaws were transported to the laboratory for the preparation of NX-size cores (54 mm).Following the coring process, core samples were trimmed on both sides, considering the available core length and maintaining a length-to-diameter ratio of approximately 2:1 for subsequent geotechnical measurements.It was ensured that both sides of each sample were identical within the specified limits.Before testing, the diameter and length of each sample were measured, the samples were weighed, and all relevant data was thoroughly recorded in a datasheet.A considerable number of samples were tested in accordance with relevant standards [21][22][23][24][25][26][27][28] to determine the mechanical and physical properties of the collected evaporitic rocks ( Table 2 and Figs. 2 and 3 ).During the SHR RB measurements, maximum precau-    tions were taken to avoid any influence from obvious fractures, discontinuities, or proximity to edges, as these factors could influence the results.The SDI tests were conducted applying both distilled water and sea water as the slaking fluid and classified based on Franklin and Chandra [29] from the 1st cycle to the 4th cycle (I d1 -I d4 ) [1] .Density ( ρ) and Unit Weight ( γ ) were measured for natural, dry, and water-saturated samples.
X-ray fluorescence (XRF) elemental analysis was conducted for powder ( < 74 μm) samples (PW 2404 with five analyzing crystals).With an accuracy of 99.99 % and a confidence limit of 96.7 %, the software programs Super Q and Semi Q were used to calculate the concentrations of the tested major elements (oxides in wt.%) [30] .

Limitations
While this dataset provides valuable information on the mechanical, physical, and geochemical properties of evaporitic rocks, its practical application in engineering decisions should carefully consider site-specific variables, project requirements, and environmental considerations such as climate, groundwater conditions, and human activities.Moreover, it focuses on evaporite rocks in Abu Dhabi and its vicinity, which does not reflect the diverse geologic setting of this area; in this context, similar results are crucial for other rock types, particularly carbonate rocks.

Fig. 1 .
Fig. 1.(a) Geological map of Abu Dhabi and sampling locations; (b) and (c) temporary excavations and boreholes; (d) and (e) rock block samples; (f) transportation of rock block samples to the laboratory.

Fig. 2 .
Fig. 2. (a) Uniaxial Compressive Strength (UCS) test on the core sample; (b) Point Load Index (PLI) test on the core sample; (c) Indirect Tensile Strength (ITS) test on the core sample; (d) Schmidt Hammer test on the rock block sample (SHV RB ) with a natural surface (NS) and saw-cut surface (SS).

Table Subject
City: Abu Dhabi (24 °0 ʹ -24 °40 ʹ N and 54 °0 ʹ -55 °0 ʹ E) The studied evaporitic rock blocks were collected from Abu Dhabi and its vicinity.The coordinates and location of each sampling site are included in Fig.1and Table1.The samples are stored and analyzed at the

Table 1
Sampling sites and the tested rock blocks from each site.

Table 2
Number of evaporitic rock blocks, mechanical and physical tests.